fix clear_phi(), replace it by kill_instruction()

clear_phi() only replaces a phi-node's sources by VOID
without adjusting the usage of these sources.
As such it can't be used for cleaning things before
removing an OP_PHI.

Fix this by replacing calls to clear_phi() by calls
to kill_instruction().

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Christopher Li <sparse@chrisli.org>
1 file changed